Flux for use in soldering.



wrnniimu AGKEBMANN, or BERLIN, GERMANY.

FLUX FOR USE IN SOLDERING.

No Drawing.

To all whom it may concern:

Be it known that I, WILHELM AGKER- MANN, chemist, citizen of Germany,subject of the King of Prussia and Emperor of Germany, residing atWinsstrasse 35, Berlin in the Kingdom of Prussia and Empire of Germany,have invented new and useful Improvements in Fluxes for Use inSoldering, of which the following is a specification.

The present invention relates to fluxes for use in soldering, and animportant object is to provide a method for manufacturing a materialsimilar to silicic water-glass.

If boracic acid is combined with an alkali within the limits of 3 to 4molecules of anhydrous boracic acid (B 0 to 1 molecule of alkali, forexample sodium oxid (Na' O), it is possible to make, with a quantity ofwater nearly amounting to the weight of the anhydrous substance,transparent viscous syrups which remain liquid even at ordinarytemperatures for a comparatively long time, under certain circumstancesfor. days and weeks. An alkali or any alkaline combination, as forinstance, carbonate of soda or borax, may be used and combinations ofboracic acid. Preferably aqueous materials with known contents ofanhydrous substance are applied, adding only an additional quantity ofwater. For example, a mixture of 1 part by wei ht of commercial aqueousboracic acid (B +3H O) and 3 parts by weight of ordinary borax containinten molecules of water (N21 O.2B O +10H O contains sufficient water inorder to at once form a thick syrup in the heat of-the boilingwater-bath. These syrups which have not been known heretofore have aremarkable adhesive force and leave behind, on surfaces to which theyare applied, a transparent varnish-like coat; they are a truecounterpart to silicic water-glass. This boracic water-glass isparticularly suitable as a flux for hard solders instead of borax, notonly generally, on account of its substantially increased power ofcleansing metals, but also on other grounds. Firstly, the solderingsyrup is exceedingly useful for preparing all articles which are to besoldered, especially when working on a large scale. The liquid which isas thick as oil can be applied uniformly like glue by a brush to thesurfaces to be soldered, if necessary before they are bound together,and thus one may be certain of the presence .of the flux in every partof the joint. Further,

Specification of Letters Patent. Application filed October 8, 1908.Serial No.456,712.

Patented Nov. 16, 1909.

the great adhesive force of the syru ad mits of the most extendedobjects, an even exposed parts of the same, being covered with solder,so that none of it falls ofi, even after long standin when the solder isfirmly cemented to t e object. Likewise the syrup can be used forsmaller soldering operations by dipping a match stick into the syrup anddrawin a line over the joint to be soldered and then sprinkling fineldivided solder over the line, the solder eing placed clean and exactlyin its place, as is not possible in a different manner. These syrups aresuitable for solderin all metals with hard solder, but are particularlyadvantageous for brass. Whereas borax leaves behind after the solderingvery hard crusts which can be removed qulckly only by hammering orotherwise by troublesome corrosive action, when the residues of boracicwater-glass cool they crack oil from brass and similar alloys of theirown accord and the last traces can be removed simply by a damp cloth. Inaddition, it is to be emphasized that the troublesome efi'ervescenceattached to the use of borax is not met with when boracic water-glass isused as a flux; whereas borax when heated rises like branches from-itssupport, swells up, and when sinking into the fire gives the solderanother position, the foamy structure of the freshly applied boracicwater-glass, which moreover is considerably less effervescent, remainsconnected with its basis, also sinks together much more rapidly in theglowing fusion, and the solder which may have been raised up somewhatobtains its old place. When it stands for a somewhat long time the driedcoats of the boracic water-glass are hardly blown up at all. It is to beunderstood that the boracic water-glass may also be used in its driedstate when its adhesive quality is dispensed with but withoutsacrificing its other good qualities.

I am aware that a brazing compound composed of equal parts of anhydroussodium borate and boracic anhydrid with water is known; but this mixtureis a substance quite different from my combination and does not show theproperties described above.

What I claim as my invention and desire to secure by Letters Patent is:r

1. The method of manufacturing boracic water-glass consisting in heatinga mixture containing boracic acid, an alkali and water in suchproportions that three to four molecules of anhydrous boracic acidcorrespond I sodium combination and water in such proportions that threeto four molecules of anhydrous boracic acid correspond to one moleculeof sodium oxid and to a quantity of water nearly equal to the weight ofthe anhydrous substance.

3. A hard solder flux consisting of three to four molecules of boracicacid, one molecule of an alkali, and water.

4 As a new article of manufacture, honew waterlass consisting of threeto four molecules 0 boracic acid, one molecule of SOdlllIIl oxid andwater.

5. Method of manufacturing boracic waterglass cons sting in heatin onepart by weight of aqueous. boracic acid ?B,O,+3H O) with. three parts byweight of borax 'contamin ten molecules of water (Na,O.2B,p,+-10H,

In testimony whereof I have hereunto set I my hand in presence of twosubscribing .ZWILHELM ACKERMANN. t Witnesses: I

Hnnar \Hasm.

Wommma Hanna wltnesses.

